Accessories Always on With Fuse In

[BrankoM36]

Another one of many problems Ive had with my 93 325i is a gremlin in the fuse box.Fuse #9, the panel says it controls the radio but when its plugged in every electronic in the car turns on aside from the lights. The gauge cluster, the radio, the lights for the window switch, and obc are all on. not sure what its all about its very frustrating. the radio also doesnt keep memory i think because that fuse is never in, otherwise the battery would drain. everything works fine when the car is running. Checked the constant power wire for the radio and it gets nothing, again likely due to the fuse, but why would the gauge cluster and radio turn back on when the fuse is in. I can maybe understand at least the radio since it would be related to the fuse but the all other instruments too just irks me. Hate electrical problems.

[shogun]

Fuse #9 is for
radio/ CD player
radio/HiFi
for the instrument cluster there are fuses 22 + 27
http://wedophones.com/Manuals/BMW/1993%20BMW%20318i%20-%20318is%20-%20325i%20-%20325is%20%20Electrical%20Troubleshooting%20Manua l.pdf
check the wirings

[BrankoM36]

Thank you, ill definitely do some reading and check back on it in all the fuses have been replace but got wiring.

[JDStrickland]

1.) A fuse that has failed will result in whatever circuit it goes to does not work. You will never find a failed fuse that gives, "does not turn off," symptoms.
2.) F9 (20A) goes entirely to the radio components, except that there is a branch that goes to a thing called the Unloader Relay. I do not know what the unloader relay does, or where it is located. My schematic indicates that it is for the '93 only. (This does not mean that the unloader relay is not used in other years, it only means that it might be in another branch of the schematic diagrams.)

Assuming that the unloader relay is a part of the sleep circuit -- the car shuts down after 16 minutes of being turned off but some load remains on when the car expects it to be off -- then it makes sense that the relay has arced so that the contacts remain closed and power is supplied to various circuits that are downstream.

Let's say that you pull in to a place to park and the radio has some interesting content being played, so you turn the key off but do not remove the key and open the doors, the radio plays and dome lights remain on for 16 minutes, then the sleep timer times out and everything shuts off. The idea is that the car does not want stuff to remain on and deplete the battery, so it is programmed to think that having stuff on for more than 16 minutes is implausible and the loads ate turned off. I'm not certain of this, but it would be the job of something called an unloader relay that would do this. (I am certain that stuff turns off after 16 minuts, I am not certain tha the unlader relay is responsible for this action.) Your description of the symptom set would follow my description of the sleep timer.

[shogun]

The unloader relay de-powers other devices when the starter is used so that all the battery's amps are available to the starter, maybe that is defective